1. Field of the Invention
This present invention generally relates to portable information processing apparatuses having hard disk drives and, more particularly, to a portable information processing apparatus which an operator operates on the table after carrying; the operator sitting on the chair operates on his/her knees; the operator operates on his/her palm; or the operator operates in a handheld state by one hand or both hands.
2. Description of the Related Art
The portable information processing apparatus having the hard disk drive is in a danger state to drop down in error as compared with an information processing apparatus set on the table, because the portable information processing apparatus is operated on the operator""s knees after being carried or in the handheld state by one hand.
Furthermore, the impact resistance of the hard disk drive is low due to its mechanisms. The limit of the power of the impact resistance of the hard disk drive is about 100 G at the highest when it operates, and is about 300 G to 500 G when it does not operate.
If an impact having a strength beyond the limit is applied to the hard disk drive, the recording of information will be disrupted due to unwanted movement of the slider, and a surface of a recording area of a hard disk will be scratched by the slider that touches with the hard disk.
Therefore, preventive measures against the drop (for instance, to inhibit information from being recorded on the hard disk drive and to take the slider to a withdrawal area of the hard disk) are demanded for the portable information processing apparatus having the hard disk drive.
Also, during the progress of the operation of the portable information processing apparatus on the table, the operator may turn a direction of the portable information processing apparatus by both hands and may pick it up from the table in order to show indications on the screen of a liquid crystal panel to other persons. Accordingly, the above state should also be considered for the preventive measures against the drop.
Generally, a way to protect against damage due to drop of the portable information processing apparatus having the hard disk drive is to incorporate an acceleration sensor into the portable information processing apparatus, detect dropping of the portable information processing apparatus by an output of the acceleration sensor, and take the slider from the recording area to the withdrawal area of the hard disk by activating the actuator.
There is, however, a possibility that there may not be enough time to take the slider to the withdrawal area of the hard disk, because the activating of the actuator starts after the acceleration sensor detects the portable information processing apparatus dropping.
In order to solve the above problem, there are two mechanisms described in Japanese Laid-Open Patent Application No. 06-203505 for example.
One mechanism has a structure in which a gyrosensor built in the portable information processing apparatus detects the acceleration of the displacement of the portable information processing apparatus, and a control part built in the portable information processing apparatus outputs a head withdrawal signal and activates a head activator part when the detected acceleration is higher than a designated value.
The other mechanism has a structure in which a magnetic disk rotating at high speed is used as a gyro. Four pressure sensors are provided in the portable information processing apparatus and are located at four corners of the base side of the hard disk drives respectively in the mechanism. Pressure sensed by respective pressure sensors varies when the position of the portable information processing apparatus is inclined. A control part outputs a head withdrawal signal and activates a head activator part when the detected pressure is higher than a designated value.
According to the respective mechanisms, the magnetic head starts moving to the withdrawal area on the magnetic disk when the portable information processing apparatus starts dropping, so that the magnetic head and the recording area of the magnetic disk can be prevented from being damaged by impact caused when the portable information processing apparatus drops to the floor.
However, the two mechanisms only indirectly detect the portable information processing apparatus leaving the table by variation of the acceleration. This is because one mechanism utilizes the gyrosensor and the other mechanism utilizes the magnetic disk rotating at high speed as gyro and the pressure sensors detecting variation in pressure. Accordingly, the above mechanisms have a problem with respect to sensitivity. More particularly, it is difficult to detect, with high reliance, the portable information processing apparatus dropping from the table or the operator""s knees just after the start of dropping.
Therefore, there is a possibility that the gyrosensor may not detect the portable information processing apparatus dropping although the portable information processing apparatus is actually dropping. Thus, the magnetic head and the recording area of the magnetic disk may be damaged by impact caused when the portable information processing apparatus drops to the floor.
Besides, in a case where the operator turns the direction of the portable information processing apparatus by both hands and picks it up from the table in order to show indications on the screen of the liquid crystal panel to other persons during the progress of the operation on the table, there is a possibility that the control part may decide that the portable information processing apparatus has started dropping.
Accordingly, in the case where the control part decides that the portable information processing apparatus has started dropping when the operator turns the direction of the portable information processing apparatus by both hands and picks it up from the table, there is a problem that it is delayed to start an action of the portable information processing apparatus corresponding to a next operation after returning it on the table.
Accordingly, it is a general object of the present invention is to provide a novel and useful portable information processing apparatus in which the problems described above are eliminated.
Another and more specific object of the present invention is to provide a portable information processing apparatus having high reliability to decide that the portable information processing apparatus has started dropping.
To carry out the object, the portable information processing apparatus comprises a touch sensor or a pressure sensor provided at a bottom side of a housing, and a deciding device deciding based on an output signal of said sensor that said portable information processing apparatus is in a state where said portable information processing apparatus is normal and dropping, wherein said deciding device comprises a memory memorizing a true value table and a comparing device comparing said output signal of said sensor with said true value table which is read out from said memory.
Further object of the present invention is to provide a portable information processing apparatus which is applicable to vary a standard for deciding that said portable information processing apparatus has started dropping based on a state where said portable information processing apparatus is used.
To carry out the object, the memory has a construction to be able to write in optionally, if desired.
Another object of the present invention is to provide an electric device which is applicable to be protected in case that said electric device falls on the floor. To carry out the object, the portable information processing apparatus, has a housing with a hard disk drive inside, and also has a control device controlling the portable information processing apparatus to prohibit writing in a first mode and then enter in a withdrawal mode in case the deciding device decides that the portable information processing apparatus is dropping.
Other and further objects of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.